Children and adolescents currently grow up in a technology- and media-rich society with computers, tablets, smartphones, etc. used daily. Thus, interventions applying electronic media to prevent childhood obesity are contemporary. Available studies applying electronic media are however heterogeneous in terms of applied medium and duration. Positive effects on body composition were not observed, but only on certain lifestyle-relevant behaviours. In addition, these effects could only be seen in the short term. Follow-up data are currently scarce.